Stage 12: Gaillac to Cap'Decouverte - 30 miles (47km)
Jan Ullrich impressively claimed the first individual time trial of this year's Tour de France to move up to second place overall.
The German beat leader Lance Armstrong by one minute 36 seconds and cut the American's lead to just 34 seconds in the process.
Alexandre Vinokourov, who was second overnight, dropped to third, but only trails Armstrong by 51 seconds after he finished third, just over two minutes behind Ullrich.
"From the start I never thought I could win this time
trial," Ullrich said.
"I have never beaten Armstrong in a time trial in the Tour
before, and I did it now, in my comeback year.
"I have no words to express the joy I'm feeling."
It has been five years since the Bianchi team leader has won a time trial but Ullrich was back to his blistering best on stage 12.
Armstrong and his US Postal team had guessed that Ullrich would be the major threat over the 47km stretch.
And the Texan admitted after the race that he had had his work cut out trying to chase down the target set by Ullrich.
"It's a very difficult day," said an exhausted Armstrong.
Ullrich's performance means Armstrong will be under far more pressure than he is used to as the race heads into the Pyrenees mountains on Saturday.
Britain's David Millar moved up to 14th overall in the standings, 9:34 behind Armstrong.
Millar put in a creditable performance on the stage, finishing in seventh place, 3:55 off Ullrich's time, but he faded in the closing stages.
"I've been sick since the rest day and just
couldn't breathe during the time trial," Millar said.
"I set off good, but after 20 kilometres my plans all went
up in smoke.
"It was very hot today but to be honest it was the
least of my worries, I just couldn't breathe.
"It's allergies or bronchitis or something."